Metaphorical expressions as defined by Conceptual Metaphor Theory are frequently used in all sorts of texts, including real-world school books. This study investigates the comprehension of different types of metaphorical expressions by different groups of 15-year-old students in Norway. 50 metaphorical expressions were selected from nine textbooks in lower secondary school and presented to 400 students in a multiple choice task. About 40% of these students had Norwegian as their second language. A questionnaire relating to language practice and school experience provided the basis for categorizing the students into several groups. A comparison of the results from different groups of students showed that the linguistic minority students as a group understood substantially fewer expressions than their peers with Norwegian as their mother tongue, and that some of the language minority groups understood fewer than others. The metaphorical expressions were categorized into different sets according to several variables, relating to the expressions themselves and to the contexts in which they appeared in the introductory phrases of the multiple choice items. Some sets of expressions turned out to be more difficult than others. The minority students&#8217; choice of wrong alternatives seemed to be influenced by the resemblance in form between single words in the introductory phrase and in the distracter. This study shows the need a) to take the diversity of the metaphorical expressions into account in studies of metaphorical comprehension as urged by Gibbs (this volume) and b) to focus on vocabulary of all sorts in education.